here<\/a>. <\/p>\nRecently, I wanted to define a bean, where the bean’s constructor required me to call a method on another bean to be instantiated.<\/p>\n
To make it more clear, Let us consider a class A which has a method getApi() in it. Consider another class B, now to define class B as a spring bean we need to call getApi() method of class A (which itself is a spring bean) in the constructor of B.<\/p>\n
In code the dependency is like this<\/p>\n
[java]
\nA a = new A()
\nB b = new B(a.getApi())
\n[\/java]<\/p>\n
The only complication being both A and B needed to be spring defined singleton beans in resources.groovy.<\/p>\n
Lets see how we can solve this problem, In resources.groovy <\/p>\n
[java]
\na(A)
\nb(B) { beanDefinition ->
\n beanDefinition.constructorArgs = ["#{a.getApi()}"]
\n}<\/p>\n
[\/java]<\/p>\n
In the above code, we defined the constructor arguments for class B, as a list containing only 1 element, which is a method invoked on bean “a”. <\/p>\n
Now to use these 2 beans in a third class “C” is trivial, in resources.groovy just do<\/p>\n
[java]<\/p>\n
c(C) {
\n a = ref("a")
\n b = ref("b")
\n}
\n[\/java]<\/p>\n
~~Cheers~~<\/p>\n
Sachin Anand
\nsachin[at]intelligrape[dot]com
\n@babasachinanand<\/p>\n","protected":false},"excerpt":{"rendered":"
In Grails, We can define custom beans in resources.groovy. A simple bean definition looks like [java] myClass(MyClass) [\/java] Read more about them here. Recently, I wanted to define a bean, where the bean’s constructor required me to call a method on another bean to be instantiated. To make it more clear, Let us consider a […]<\/p>\n","protected":false},"author":14,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":19},"categories":[7],"tags":[1573,1569,1572,1570,1571,4841],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/16323"}],"collection":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/users\/14"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/comments?post=16323"}],"version-history":[{"count":0,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/16323\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/media?parent=16323"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/categories?post=16323"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/tags?post=16323"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}